import { InputValueDefinitionNode, InputObjectTypeDefinitionNode, EnumValueDefinitionNode, EnumTypeDefinitionNode } from "graphql";

function getFieldArgument(fieldName: string): InputValueDefinitionNode {
  return {
    kind: "InputValueDefinition",
    name: {
      kind: "Name",
      value: fieldName
    },
    type: {
      kind: "NamedType",
      name: {
        kind: "Name",
        value: "Operators"
      }
    },
    defaultValue: null,
    directives: []
  };
}

function getWhereType(name: string, fieldNames: string[]): InputObjectTypeDefinitionNode {
  const def: InputObjectTypeDefinitionNode = {
    kind: "InputObjectTypeDefinition",
    name: {
      kind: "Name",
      value: name
    },
    directives: [],
    fields: [
      {
        kind: "InputValueDefinition",
        name: {
          kind: "Name",
          value: "OR"
        },
        type: {
          kind: "ListType",
          type: {
            kind: "NonNullType",
            type: {
              kind: "NamedType",
              name: {
                kind: "Name",
                value: name
              }
            }
          }
        },
        defaultValue: null,
        directives: []
      },
      {
        kind: "InputValueDefinition",
        name: {
          kind: "Name",
          value: "AND"
        },
        type: {
          kind: "ListType",
          type: {
            kind: "NonNullType",
            type: {
              kind: "NamedType",
              name: {
                kind: "Name",
                value: name
              }
            }
          }
        },
        defaultValue: null,
        directives: []
      }
    ]
  };

  fieldNames.forEach((fieldName) => {
    (def.fields as InputValueDefinitionNode[]).push(getFieldArgument(fieldName));
  });

  return def;
}

function getEnumValueDefinition(option: string): EnumValueDefinitionNode {
  return {
    kind: "EnumValueDefinition",
    name: {
      kind: "Name",
      value: option
    },
    directives: []
  };
}

function getOrderByEnum(name: string, fields: string[]): EnumTypeDefinitionNode {
  const options = [];
  fields.forEach((fieldName) => {
    options.push(`${fieldName}_ASC`);
    options.push(`${fieldName}_DESC`);
  });
  return {
    kind: "EnumTypeDefinition",
    name: {
      kind: "Name",
      value: name
    },
    directives: [],
    values: options.map(getEnumValueDefinition)
  };
}

export function getFilterDefinitions(fieldNames: string[], orderByEnumName: string, whereFilterName: string) {
  return [getOrderByEnum(orderByEnumName, fieldNames), getWhereType(whereFilterName, fieldNames)];
}